This invention relates to synchronous electric motor control systems and to gyroscope apparatus including such control systems.
Many arrangements have been proposed for controlling the speed of an electric motor so that it is maintained substantially constant. Difficulties, however, are experienced in reducing the minor fluctuations of motor speed, or hunting, such as is caused by defects or wear in the motor bearings. Problems also occur in starting the motor from its stationary state when some motor control circuits are used.